# HA and bonding - which mode ? **URL:** \ **Category:** SLES Configure-Administer\ **Created:** [December 13, 2011, 4:56pm UTC](https://forums.suse.com/t/ha-and-bonding-which-mode/21899 "2011-12-13T16:56:02Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![System1](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@System1](https://forums.suse.com/u/System1)\ **Post date:** [December 13, 2011, 4:56pm UTC](https://forums.suse.com/t/ha-and-bonding-which-mode/21899/1 "2011-12-13T16:56:02Z")
Hi, ## i’d like to create a HA-Setup having two nodes. Every offered service will run in a dedicated VM. Both servers have each two network adapters combines to a bond. Furthermore i have two switches for not having one switch as a SPOF. Every slave of the bond should be connected to a different switch. Live-Migration of the vm’s (about 10) should be possible, and hopefully not to slow. If possible, i like to increase bandwith AND availibility with the bond-device. ‘Link aggregation - Wikipedia, the free encyclopedia’ ([http://en.wikipedia.org/wiki/Link\_aggregation](http://en.wikipedia.org/wiki/Link_aggregation)) says: “With modes balance-rr, balance-xor, broadcast and 802.3ad all physical ports in the link aggregation group must reside on the same logical switch, which in most scenarios will leave a single point of failure when the physical switch to which both links are connected goes offline. Modes active-backup, balance-tlb, and balance-alb can also be set up with two or more switches.” This is a clear statement. But the kerneldocumentation (/usr/src/linux/Documentation/networking/bonding.txt) states something different: "11.2.1 HA Bonding Mode Selection for Multiple Switch Topology In a topology such as the example above, the active-backup and broadcast modes are the only useful bonding modes when optimizing for availability; the other modes require all links to terminate on the same peer for them to behave rationally. active-backup: This is generally the preferred mode, particularly if the switches have an ISL and play together well. If the network configuration is such that one switch is specifically a backup switch (e.g., has lower capacity, higher cost, etc), then the primary option can be used to insure that the preferred link is always used when it is available. broadcast: This mode is really a special purpose mode, and is suitable only for very specific needs. For example, if the two switches are not connected (no ISL), and the networks beyond them are totally independent. In this case, if it is necessary for some specific one-way traffic to reach both independent networks, then the broadcast mode may be suitable." alb-balancing and tlb-balancing are not mentioned here. And i think i don’t have an ISL and if i have one, i don’t want to use one. ‘Cisco Inter-Switch Link - Wikipedia, the free encyclopedia’ ([http://en.wikipedia.org/wiki/Cisco\_Inter-Switch\_Link](http://en.wikipedia.org/wiki/Cisco_Inter-Switch_Link)) says: “… the use of ISL for new sites is deprecated by Cisco”. Can i use alb-balancing or tlb-balancing for my bond, although the kernel documentations does not mention it ? Is alb-balancing or tlb-balancing able to support both ? Increase of bandwith AND availibility ? Thanks for any answer. Bernd ## – berndgsflinux berndgsflinux’s Profile: [http://forums.novell.com/member.php?userid=5742](http://forums.novell.com/member.php?userid=5742) View this thread: [http://forums.novell.com/showthread.php?t=449517](http://forums.novell.com/showthread.php?t=449517) ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [December 17, 2011, 9:48pm UTC](https://forums.suse.com/t/ha-and-bonding-which-mode/21899/2 "2011-12-17T21:48:14Z")
berndgsflinux, It appears that in the past few days you have not received a response to your posting. That concerns us, and has triggered this automated reply. Has your problem been resolved? If not, you might try one of the following options: - Visit [http://support.novell.com](http://support.novell.com) and search the knowledgebase and/or check all the other self support options and support programs available. - You could also try posting your message again. Make sure it is posted in the correct newsgroup. ([http://forums.novell.com](http://forums.novell.com)) Be sure to read the forum FAQ about what to expect in the way of responses: [http://forums.novell.com/faq.php](http://forums.novell.com/faq.php) If this is a reply to a duplicate posting, please ignore and accept our apologies and rest assured we will issue a stern reprimand to our posting bot. Good luck! Your Novell Product Support Forums Team [http://forums.novell.com/](http://forums.novell.com/) ---
**Author:** ![worshamn](https://avatars.discourse-cdn.com/v4/letter/w/e47c2d/32.png) [@worshamn](https://forums.suse.com/u/worshamn)\ **Post date:** [September 12, 2012, 7:38pm UTC](https://forums.suse.com/t/ha-and-bonding-which-mode/21899/3 "2012-09-12T19:38:45Z")
Was searching through forums and this thread is almost exactly the same problem that we were looking for an answer to --except we have 4 nics on 2 switches. But unfortunately looks like you never received an answer. Did you ever get your answer of what mode to use to get increased bandwidth and availability? ---
**Author:** ![KEVIN1](https://avatars.discourse-cdn.com/v4/letter/k/a9adbd/32.png) [@KEVIN1](https://forums.suse.com/u/KEVIN1)\ **Post date:** [September 13, 2012, 2:49am UTC](https://forums.suse.com/t/ha-and-bonding-which-mode/21899/4 "2012-09-13T02:49:12Z")
worshamn wrote: [color=blue] > Was searching through forums and this thread is almost exactly the > same problem that we were looking for an answer to --except we have 4 > nics on 2 switches. But unfortunately looks like you never received > an answer. Did you ever get your answer of what mode to use to get > increased bandwidth and availability?[/color] Have you tried searching the knowledgebase? [http://www.novell.com/support/](http://www.novell.com/support/) I did a quick search for “bonding” and got quite a few hits including this: TID 3929220 How To Configure Bonding on Novell Linux products [http://www.novell.com/support/kb/doc.php?id=3929220](http://www.novell.com/support/kb/doc.php?id=3929220) – Kevin Boyle - Knowledge Partner If you find this post helpful and are using the web interface, show your appreciation and click on the star below… ---
**Author:** ![Jens-U](https://avatars.discourse-cdn.com/v4/letter/j/d78d45/32.png) [@Jens-U](https://forums.suse.com/u/Jens-U)\ **Post date:** [September 17, 2012, 4:30pm UTC](https://forums.suse.com/t/ha-and-bonding-which-mode/21899/5 "2012-09-17T16:30:42Z")
Hi worshamn, we’ve decided to go for 802.3ad (AKA “LACP”) for redundant links. Please note that all docs say that this type of bonding must terminate in the same _logical_ switch, which does not necessarily lead to a SPOF: Nowadays switches are prepared for HA, too, you can create a single “logical switch” from multiple hardware switches (be it either stackables on the lower end or an aggregation of multiple modular switches on the higher end of the product lines). Regards, Jens ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [September 18, 2012, 2:00am UTC](https://forums.suse.com/t/ha-and-bonding-which-mode/21899/6 "2012-09-18T02:00:25Z")
On 09/17/2012 08:34 AM, jmozdzen wrote:[color=blue] > Hi worshamn, > > we’ve decided to go for 802.3ad (AKA “LACP”) for redundant links. > Please note that all docs say that this type of bonding must terminate > in the same _logical_ switch, which does not necessarily lead to a SPOF: > Nowadays switches are prepared for HA, too, you can create a single > “logical switch” from multiple hardware switches (be it either > stackables on the lower end or an aggregation of multiple modular > switches on the higher end of the product lines).[/color] Many switches will do Multi-Chassis Link Aggregation (MCLAG or MLAG)… so you can have your LACP going to different switches as long as they support that. (which may have been what you were saying) ---
**Author:** ![Jens-U](https://avatars.discourse-cdn.com/v4/letter/j/d78d45/32.png) [@Jens-U](https://forums.suse.com/u/Jens-U)\ **Post date:** [September 18, 2012, 12:32pm UTC](https://forums.suse.com/t/ha-and-bonding-which-mode/21899/7 "2012-09-18T12:32:52Z")
[QUOTE=cjcox;6930]On 09/17/2012 08:34 AM, jmozdzen wrote:[COLOR=blue] > […][/COLOR] > Many switches will do Multi-Chassis Link Aggregation (MCLAG or MLAG)… so you > can have your LACP going to different switches as long as they support that. > (which may have been what you were saying)[/QUOTE] yes, MCLAG is one type of implementation I was thinking of - and which I believe to be usually available in the “more expensive routers”. If you’re on a low budget and need a solution for a small environment, you might use stackable switches, too - some already implement this at a rather low price (but be certain to check the specific type of implementation, some vendors restrict LAGs to a single module!). Regards, Jens ---
**Author:** ![worshamn](https://avatars.discourse-cdn.com/v4/letter/w/e47c2d/32.png) [@worshamn](https://forums.suse.com/u/worshamn)\ **Post date:** [September 24, 2012, 11:46pm UTC](https://forums.suse.com/t/ha-and-bonding-which-mode/21899/8 "2012-09-24T23:46:49Z")
Thank you for the repsonses, we did end up going with 802.3ad, bonding nics 1 and 2 together and 3 and 4, the 2 groups are on 2 different switches, the switches have been setup to be aware of the aggregation. Then bonding those two bonds together into an active-backup mode.